This invention relates to the measurement of temperature by the use of resistance thermometers and more particularly to measurements using resistance thermometers of the three-lead type. This invention is an improvement of the temperature measuring means disclosed in U.S. Pat. No. 3,913,403 issued to S. A. Arcara on Oct. 21, 1975. The disclosure of that patent is hereby incorporated by reference as a part of the description of the present invention. Particular reference should be made to the specification of the referenced U.S. patent from column 1 through column 3, as it deals with FIGS. 1 through 4 of the patent.
It is an object of the present invention to provide an improved system for measuring the resistance of a resistance thermometer of the three-lead type.
More particularly, it is an object of this invention to provide apparatus for making such measurements with three-lead resistance thermometers of varied types with a minimum of common mode interference.
It is another object of this invention to provide a means for making a temperature measurement with a resistance thermometer in a manner which will provide for a linear temperature scale on the voltage measuring instrument utilized to indicate the temperature being measured by the resistance thermometer.